Skeberis, C., Xenos, D. T., Xenos, T. D., Contadakis, M. E., Arabelos, D. and Chatzopoulou, G. (2012) “Application of empirical mode decomposition to very low frequency signals for identification of seismic-ionospheric precursor phenomena”, Annals of Geophysics, 55(1). doi: 10.4401/ag-5312.